1. Field of the Invention
The present invention relates to a memory system which has a field programmable unit.
2. Description of the Related Art
In order to make changeable logic for implementing a predetermined circuit function through a program, a logic device has been proposed which has a field programmable unit. This kind of logic device is used together with a program memory unit which stores a program for constructing logic.
Also, a programmable circuit has been proposed which has a program memory unit composed of a field programmable unit and semiconductor memory (for example, see Japanese Unexamined Patent Application Publication No. 11-205125). The semiconductor memory stores a program for constructing the logic of the field programmable unit during the non-operation of the programmable circuit. The program stored in the semiconductor memory is transmitted to the field programmable unit so as to construct the logic of the field programmable unit. When the programmable circuit operates, that is, after the program is transmitted to the field programmable unit, the semiconductor memory is used as a random access memory. This accordingly eliminates the need for a dedicated memory to store the program. The field programmable unit in which the logic has been constructed performs an image compression processing, for example.
However, in the conventional memory system having the field programmable unit and the semiconductor memory, the operation specification of the semiconductor memory is fixed and is not changable by the logic of the field programmable unit.